Patent US3550071A successfully refreshed from Google Patents.
US3550071A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transducer system
Assignee: Fried Krupp AG
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Filing: 1969-05-09
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Granted: 1970-12-22
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Expires: 1989-05-09
Abstract
No abstract record available.
Inventors
- 👤 Hans Schlemm
- 👤 Peter Mertens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:58
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/222
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-12-21 | 1974-06-22 | 1974-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-12-21 | 1978-06-22 | 1978-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-12-21 | 1982-06-22 | 1982-12-22 | $7700.00 | Window Closed / Lapsed |